Recently, as a new memory device, a nonvolatile semiconductor memory device called ReRAM (Resistance Random Access Memory) is noted. The ReRAM uses resistance memory elements which have a plurality of resistance states of different resistance values and have the resistance states changed by external application of electric stimuli, and is used as a memory element by corresponding the high resistance state and the low resistance state of the resistance memory elements to, e.g., “0” and “1” of information. The ReRAM, which can realize high speed, large capacities, low electric power consumption, etc., is very prospective.
Related references are as follows:
A. Beck et al., “Reproducible switching effect in thin oxide films for memory applications”, Applied Physics Letters, Volume 77, Number 1, p. 139-141 (2000), and
I. G. Baek et al., “Highly Scalable Non-volatile Resistive Memory using simple Binary Oxide Driven by Asymmetric Unipolar Voltage Pulses”, IEDM Technical Digest, p. 587-590 (2004).